The University of Pennsylvania School of Medicine proposes to expand BSL3 laboratory capacity and to renovate an existing BSL2 vivarium, bringing it to BSL3 standards, to accommodate the rapid growth in NIHfunded research for emerging infectious diseases and biodefense that supports the work by a large number of Penn investigators. While both research and vivarium space have been greatly expanded in recent years, construction of new BSL3 facilities have not kept pace with the unexpectedly rapid growth in research and research training on emerging infectious diseases and HIV at the School of Medicine. Penn investigators play a major role in the Middle Atlantic Regional Center of Excellence (RCE) for Biodefense and Emerging Infectious Diseases Research, hold an NIH training grant on Emerging Infectious Diseases, hold awarded research grants that support work on West Nile, SARS, Ebola, Yersiniapestis, Anthrax, Crimean Congo Hemorrhagic fever virus and poxviruses, and have grants to support work on emerging infectious agents. Research at Penn on emerging infectious diseases and, to a lesser extent HIV, is greatly constrained by limited BSL3 capacity. There is only a single, common use BSL3 laboratory at the School of Medicine. This facility opened in 2000, and has been overwhelmed by large numbers of users. In addition, there is not a single animal BSL3 (ABSL3) facility at Penn. As a result, Penn investigators cannot perform small animal studies with BSL3 agents. To make it possible for Penn investigators to continue to expand their work on emerging infectious agents, biodefense and HIV, we propose to construct a new 500 sq. ft. BSL3 laboratory, renovate and double the size of our major BSL3 facility, and convert an ABSL2 into a modern ABSL3 facility.